piskel/js/drawingtools/Circle.js

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/*
* @provide pskl.drawingtools.Circle
*
* @require pskl.utils
*/
(function() {
var ns = $.namespace("pskl.drawingtools");
ns.Circle = function() {
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this.toolId = "tool-circle";
this.helpText = "Circle tool";
// Circle's first point coordinates (set in applyToolAt)
this.startCol = null;
this.startRow = null;
};
pskl.utils.inherit(ns.Circle, ns.BaseTool);
/**
* @override
*/
ns.Circle.prototype.applyToolAt = function(col, row, color, frame, overlay) {
this.startCol = col;
this.startRow = row;
// Drawing the first point of the rectangle in the fake overlay canvas:
overlay.setPixel(col, row, color);
};
ns.Circle.prototype.moveToolAt = function(col, row, color, frame, overlay) {
overlay.clear();
if(color == Constants.TRANSPARENT_COLOR) {
color = Constants.SELECTION_TRANSPARENT_COLOR;
}
// draw in overlay
this.drawCircle_(col, row, color, overlay);
};
/**
* @override
*/
ns.Circle.prototype.releaseToolAt = function(col, row, color, frame, overlay) {
overlay.clear();
if(frame.containsPixel(col, row)) { // cancel if outside of canvas
// draw in frame to finalize
this.drawCircle_(col, row, color, frame);
}
};
ns.Circle.prototype.drawCircle_ = function (col, row, color, targetFrame) {
var circlePoints = this.getCirclePixels_(this.startCol, this.startRow, col, row);
for(var i = 0; i< circlePoints.length; i++) {
// Change model:
targetFrame.setPixel(circlePoints[i].col, circlePoints[i].row, color);
}
};
ns.Circle.prototype.getCirclePixels_ = function (x0, y0, x1, y1) {
var coords = pskl.PixelUtils.getOrderedRectangleCoordinates(x0, y0, x1, y1);
var xC = (coords.x0 + coords.x1)/2;
var yC = (coords.y0 + coords.y1)/2;
var rX = coords.x1 - xC;
var rY = coords.y1 - yC;
var pixels = [];
var x, y, angle;
for (x = coords.x0 ; x < coords.x1 ; x++) {
angle = Math.acos((x - xC)/rX);
y = Math.round(rY * Math.sin(angle) + yC);
pixels.push({"col": x, "row": y});
pixels.push({"col": 2*xC - x, "row": 2*yC - y});
}
for (y = coords.y0 ; y < coords.y1 ; y++) {
angle = Math.asin((y - yC)/rY);
x = Math.round(rX * Math.cos(angle) + xC);
pixels.push({"col": x, "row": y});
pixels.push({"col": 2*xC - x, "row": 2*yC - y});
}
return pixels;
};
})();